I am not a science teacher, nor do I play one on television. However, I was passed this website from a fellow "tweeter" and thought it worth sharing. http://www.periodicvideos.com/ It appears to have short videos clips for all the elements on the periodic table. I have not played with it enough to see if you can pull the videos off the site. They look to be through youtube so you could grab them from there using a downloader. Personally, I like using http://www.savevid.com/ Enjoy!